QR codes, JSON diff/format, hashes, JWT, cron, timestamps, placeholders, flowcharts, forms, regex.
Scored across 12 tools
Each tool has a clearly distinct purpose: timestamps, JSON diffing, encoding, cron, flowcharts, JSON formatting, colors, forms, QR, placeholder images, regex. Even the two JSON tools (diff_json vs format_json) are cleanly separated by compare-versus-validate semantics, and the generate_* group targets different artifact types. No meaningful overlap exists.
All tools share the usesignal_ prefix and follow a verb_noun pattern (convert_timestamp, diff_json, format_json, generate_qr, test_regex). Two tools break the pattern with noun-only names (flowchart, placeholder_image), a minor deviation that is still readable.
12 tools is well-scoped for a developer utility toolbox, with each tool earning its place by covering a distinct transform. No redundancy or filler tools are present.
For a stateless utility toolbox the surface is broad, covering timestamps, JSON, encoding/hashing, cron, regex, QR, colors, forms and placeholders with no lifecycle gaps (CRUD does not apply). Minor utility gaps exist (e.g. UUID or unit/number-base conversion), but agents can work around them.
Convert a Unix timestamp (seconds or milliseconds) or an ISO 8601 date into ISO, UTC, epoch seconds/milliseconds, a relative time and the local time in a given time zone.
Inputs: value (required), timeZone.
Compare two JSON documents structurally and list every added, removed and changed value with its JSONPath. Numbers compare exactly. Arrays match by content by default, so an inserted item shows as one addition; use arrays:"position" to compare index by index.
Inputs: left (required), right (required), arrays.
Exact text transforms: Base64 encode/decode (UTF-8), URL encode/decode, decode a JWT header and payload with readable exp/iat/nbf dates (the signature is not verified), or hash text with MD5, SHA-1, SHA-256 and SHA-512. Use this instead of computing hashes or Base64 by hand.
Inputs: text (required), operation (required).
Explain a standard 5-field cron expression (minute hour day-of-month month day-of-week) in plain English and list its next run times in a given time zone, handling daylight saving time.
Inputs: expression (required), count, timeZone.
Turn JavaScript/TypeScript code, arrow steps or Mermaid-style arrows into a flowchart, returned as Mermaid source and an SVG diagram. Steps mode uses one flow per line: "Start -> Validate -> Save" and branches like "Validate -- No --> Show error".
Inputs: mode (required), input (required), direction.
Validate, pretty-print or minify JSON, optionally sorting keys. Invalid JSON reports the exact line and column; with repair (default on) it fixes common problems such as trailing commas, single quotes, comments and unquoted keys, and lists each fix.
Inputs: json (required), mode, indent, repair, +1 more.
Generate light and dark semantic color tokens from a six-digit hex brand color. Returns a shade scale, measured text contrast checks and CSS, JSON and Tailwind exports. This measures listed color pairs only, not whole-page accessibility. Call usesignal_open_workbench with the result input to preview.
Inputs: baseColor (required).
Generate an editable form from a JSON object. Returns nested field paths, JSON Schema, HTML, React JSX and config exports. Arrays and nulls use JSON textareas. Values are processed in memory; avoid secrets. To show an interactive preview, call usesignal_open_workbench with this result input.
Inputs: json (required), title, overrides.
Generate a scannable QR code for a link, text, Wi-Fi network, contact card (vCard), email, SMS, phone number, WhatsApp chat or UPI payment. Returns the encoded payload, an SVG file and a PNG preview image. values by type: url{url}; text{text}; wifi{ssid,password,security:WPA|WEP|nopass,hidden}; vcard{firstName,lastName,phone,email,org,title,website,address}; email{to,subject,body}; sms{phone,message}; phone{phone}; whatsapp{phone,message}; upi{vpa,name,amount,note}.
Inputs: type (required), values (required), dark, light, +3 more.
Show the editable useSignal UI. First call a useSignal data tool, then pass its returned input and matching tool name. Recomputes from validated inputs; no shared state.
Inputs: tool (required), input (required).
Create a placeholder image URL (served by usesignal.dev) plus HTML, Markdown and CSS snippets, for mockups, prototypes, seed data and layouts. Width and height up to 4000 px.
Inputs: width (required), height (required), text, color, +4 more.
Execute a JavaScript regular expression against text and expected match/non-match test cases. Returns indexed matches and capture groups. Flags use JavaScript semantics. Execution times out after 500ms. Call usesignal_open_workbench with result input to highlight matches.
Inputs: text (required), pattern (required), flags, tests.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Developer and text tools: JSON, QR codes, units, passwords, UUIDs, hashes, Base64, regex and more.
Developer toolkit: UUID, timestamp, unit conversion, JSON tools, and QR code (SVG). Free.
22 developer utilities: base64, hashes, JWT, JSON tools, unit conversion. Free, keyless.
300+ offline developer utilities, plus 21 AI tools with a free API key. JSON, JWT, regex, cron, SQL.
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